The Vanden Plas body was demanded by Lord Leonard who, in 1942, wanted a coach of traditionally English design that could hold its own next to the likes of Rolls-Royce and Bentley.

As a result, the Princess became forever linked with Vanden Plas, who was already well-known for his work with such brands as Rover, Rolls-Royce, Bentley, Alvis, Daimler and Lagonda. With its origins in Belgium, the firm was founded in 1870 as a small manufacturer of wheels and, later, coaches. In 1900 they were already working for the renowned brands of De Dion Bouton, Berlier, Germain and Packard. Around 1908, Vanden Plas employed 400 employees, who were charged with building around 300 special bodies per year.

In 1913, the English branch of Vanden Plas was created to build bodies under license from the parent company. When in 1946 Vanden Plas became a subsidiary of Austin Motors, they were put in charge of the Princess.

The first versions of the Princess adopted a prominent vertical grille, large Lucas P100 headlights and distinctly cut fenders on which the lights were mounted. Inside, the use of noble materials such as wood and leather were matched with luxuriously rich carpets—elements needed to compete in the British luxury saloon market.

In 1953 the Austin A135 Princess MkIII was introduced. It followed the MkII, which appeared three years earlier. The new MkIII could be best distinguished by the more fluid lines of its radiator grid. Rather than launch a brand-new model year on year, the frugal Lord Leonard, in a bid to save costs decided on incremental evolutions of the original model. To comply with his wishes, Austin Engineers reused the Somerset-Hereford doors and other components from previous versions of the Princess. This carry-over attitude is also employed by today’s car manufacturers.

Vanden Plas was also asked to make use of the existing long chassis in the design of a new body, which would be unveiled at Earls Court as the new Austin Princess 4-Liter.

The Princess six-cylinder inline engine with its famous 4-litre capacity remained unmatched. In 1956 Austin followed up with the Princess MkIV, a more modern design on which the biggest novelty was the integration of wings in the front section. In total, 350 units of the Austin A135 Princess MkIII were built.

This car was donated to the Museu do Caramulo by António Medeiros e Almeida.